ABSTRACT- It was generally thought that there was no DNA repair capacity in Mamamlian mitochondria. However, it has recently become clear that while the nature of the DNA repair processes that exist in mitochondria differ much from the DNA repair processes in the nuclues, there is capacity in mitochondria for the repair of oxidative DNA damage and for some of the DNA lesions that are introduced by gamma irradiation. These repair processes in mitochondria will be discussed and deficiencies will be related to human diseasess